The major research emphasis of this application will be to evaluate the pharmacological properties of aminotetralins and evaluation of their mechanism of action and their SAR. Initial work indicates that these cyclic analogs of dopamine are the structurally active component of apomorphine. These compounds inhibit peripheral adrenergic transmission, apparent dopamine receptor stimulation of the CNS, beta and alpha receptor agonists and serotonin receptor stimulation. Possible therapeutic development include anti-hypertensives, antiparkinson agents and bronchial dilators. Pharmacological properties and areas of SAR studies are listed as follows: 1. Apomorphine analogs (aminotetralins). We have discovered an analog, 5,6-dimorphine. We will be comparing the activity of apomorphine, M-7 and analogs for ability to inhibit adrenergic transmission at various sites. We will obtain data on relative potency, selectivity of site, mechanism of action and structural requirements. 2. These analogs exhibit central actions similar to apomorphine. We are interested in searching for selectivity, i.e. less emetic action, peripheral or central actions only, etc. 3. We have discovered that a cyclic dopamine analog is a potent relaxant of bronchial smooth muscle. We will continue to explore the pharmacological properties of this agent and the SAR of analogs. 4. We will explore analogs of N,N-dimethyldopamine as alpha-receptor stimulants. Initial data indicate these compounds also activate dopamine receptors. 5. 5,8-Dimethoxy aminotetralins are highly active in preventing pecking in pigeons that is induced by apomorphine. We will explore the mechanisms of action.